I. Field of the Invention
The present invention relates to cyclically repetitive motion generating systems and, in particular, to a mechanism which will generate a rotary output that has a combined epicycloidal and harmonic motion with a device for angular adjustment of the dwell position.
II. Description of the Prior Art
U.S. Pat. Nos. 4,089,228 and 4,020,708 are related to the present disclosure. Prior to the above reference U.S. Patents, numerous apparatuses and devices have been utilized to provide a desired motion of an output member along a prescribed path such as the linear indexing mechanism disclosed in U.S. Pat. No. 3,857,292 which is designed to achieve cycloidal motion of an output member along a linear path. Other mechanisms disclosed in the prior art generally achieve cyclically repetitive motion by utilizing complicated cam grooves and followers to accomplish predetermined acceleration, deceleration, dwell, and reversing characteristics of the output member.
To the knowledge of the inventor, such machines and, in particular, the type disclosed in U.S. Pat. No. 3,857,292 have very little flexibility in varying from the cycloidal acceleration curve so as to either increase or decrease the dwell and peak speeds of the output member. Since the dwell periods for such systems have short dwell periods due to the nature of the cycloidal output motion, the electric motor driving such a mechanical mechanism has less revolutions in which to start and stop. Consequently, electrical switches and the like which must be activated by the output member of such mechanisms are activated at a higher speed (i.e. 100 rpm) by a rotating crank member; and, thus, the life expectancy of such switching mechanisms associated with the prior art mechanical devices are considerably shortened.
In mechanical metal forming presses using a progressive die to form parts, the dwell period is used to index the work piece between stations. The short dwell period of the typical harmonic motion of a standard mechanical press, requires a feed mechanism which must rapidly advance the work piece. This limits the speed at which the press can operate and imposes heavy loads and increases the potential of failure of the feed mechanism.